Non-hydrogenated canola oil for food applications

ABSTRACT

A non-hydrogenated canola oil having superior oxidative stability and fry stability useful for food applications is disclosed, as well as seeds, plant lines and progeny thereof from which the oil is derived.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation-in-part application ofPCT/US94/04352, claiming priority under 35 USC §120, which is acontinuation-in-part application of Ser. No. 08/184,128 filed Jan. 21,1994, now abandoned, which is a continuation-in-part of Ser. No.08/054,806 filed Apr. 27, 1993, now abandoned.

FIELD OF THE INVENTION

The present invention relates to non-hydrogenated canola oil havingimproved flavor and performance attributes especially suitable for foodapplications, and to the Brassica seeds, plant lines and progeny thereoffrom which the oil is derived.

BACKGROUND

Canola oil has the lowest level of saturated fatty acids of allvegetable oils. As consumers become more aware of the health impact oflipid nutrition, consumption of canola oil in the U.S. has increased.However, generic canola oil has limited use in deep frying operations,an important segment of the food processing industry, due to itsinstability. Canola oil extracted from natural and commercial varietiesof rapeseed contains a relatively high (8%-10%) α-linolenic acid content(C_(18:3)) (ALA). The oil is unstable and easily oxidized duringcooking, which in turn creates off-flavors of the oil and compromisesthe sensory characteristics of foods cooked in such oils. It alsodevelops unacceptable off odors and rancid flavors during storage.

Hydrogenation can be used to improve performance attributes by loweringthe amount of linoleic and α-linolenic acids in the oil. In this processthe oil increases in saturated and trans fatty acids, both undesirablewhen considering health implications. Blending of oil can also be usedto reduce the α-linolenic acid content and improve the performanceattributes. Blending canola oil with other vegetable oils such ascottonseed will increase the saturated fatty acids content of the oilbut decreases the healthy attributes of canola oil.

α-Linolenic acid has been reported to oxidize faster than other fattyacids. Linoleic and α-linolenic acids have been suggested as precursorsto undesirable odor and flavor development in foods. To improve thefunctionality of canola oil, the University of Manitoba developed thecanola variety "Stellar" which has reduced α-linolenic acid (Scarth etal., Can. J. Plant Sci., 68:509-511 (1988)). The low α-linolenic acidoil was reduced in odor when heated in air, but still remainedunacceptable to the sensory panel in flavor evaluations (Eskin et al.,J. Am. Oil Chem. Soc. 66:1081-1084 (1989)). The oxidative stability ofStellar oil increased by 17.5% over the commercial variety Westar asmeasured by Active Oxygen Method (AOM) hours. (Can. J. Plant Sci. (1988)Vol. 68, pp. 509-511).

European Patent Application, EP 0 323 753 A1 describes a canola oilhaving an enhanced oleic acid content with increased heat stability incombination with other traits. The application further describes afrying oil with reduced α-linolenic acid which imparts increasedoxidative stability. No flavor and performance testing with thedescribed oil was reported.

Data which shows that oxidative stability is not solely related to fattyacid composition (described below) indicates that increased stabilitycannot be inferred from fatty acid composition. The amount ofα-linolenic acid in the oil is only one factor which controls oxidativestability and flavor stability. Thus a canola oil which has improvedstability in its flavor and performance attributes for use in foodoperations is needed. The present invention provides such an oil.

SUMMARY OF THE INVENTION

The present invention provides an oil comprising a non-hydrogenatedcanola oil having an oxidative stability of from about 37 to about 30AOM hours in the absence of antioxidants. The oil of the presentinvention also has fry stability for up to at least 64 hours. After 64hours of frying, the oil of the present invention has reduced totalpolar material content of about 23%, reduced free fatty acid content ofabout 0.7%, reduced red color development as shown by a Lovibond colorvalue of 6.7 red and reduced para-anisidine value of 125 absorbance/g.After 32 hours of frying, the oil of the present invention has reducedtotal polar material content of about 12%, reduced free fatty acidcontent of about 0.3%, reduced red color development as shown by aLovibond color of 2.7 red and reduced para-anisidine value of 112absorbance/g.

The present invention further provides a seed comprising a Brassicanapus variety containing canola oil as described above, and progenythereof.

The present invention further provides a plant line comprising aBrassica napus canola variety which produces canola oil as describedabove, and individual plants thereof.

BRIEF DESCRIPTION OF THE SEED DEPOSIT

Seed designated IMC 130 as described hereinafter was deposited on Apr.16, 1993 with the American Type Culture Collection, Rockville, Md. andwas assigned accession number 75446.

DETAILED DESCRIPTION OF THE INVENTION

The present invention provides canola oil having superior stable flavorand performance attributes when compared to known canola oils. Theinvention also provides Brassica napus seeds, and plant lines producingseeds, from which such an oil can be produced.

A canola oil of the present invention is superior in oxidative stabilityand fry stability compared to known canola oils. The superiorfunctionalities of the oil can be demonstrated, e.g., by standardizedAmerican Oil Chemists' Society (AOCS) oil testing methods. The improvedcharacteristics of the oil permit it to be used in new food products andpermit the oil to be used without hydrogenation in situations whereincreased flavor stability, oxidative stability, fry stability andshelf-life stability are desirable.

In the context of this disclosure, a number of terms are used. As usedherein, "functionality" or "performance attributes" means properties orcharacteristics of the canola oil and includes flavor stability, frystability, oxidative stability, shelf-life stability, and photooxidativestability.

Oxidative stability relates to how easily components of an oil oxidizewhich creates off-flavors in the oil, and is measured by instrumentalanalysis using accelerated oxidation methods. American Oil Chemists'Society Official Method Cd 12-57 for Fat Stability: Active Oxygen Method(re'vd 1989); Rancimat (Laubli, M. W. and Bruttel, P. A., JOACS63:792-795 (1986)); Joyner, N. T. and J. E. McIntyre, Oil and Soap(1938) 15:184 (modification of the Schaal oven test). Oils with highoxidative stability are considered to be premium oils for shelf stableapplications in foods, i.e., spray coating for breakfast cereals,cookies, crackers, fried foods such as french fries, and snack foodssuch as potato chips.

Fry stability relates to the resistance to degeneration of the oilduring frying. Fry stability can be evaluated by measuring parameterssuch as total polar material content, free fatty acid content, colordevelopment and aldehyde generation. "Fry life" is determined bysequentially frying products in an oil and performing a sensory analysisof the flavor of the fried products. Fry life is measured as the lengthof time the oil is used for frying before the sensory analysis of afried product degrades to a predetermined score. Oils for restaurants,hospitals and large institutions primarily are used for frying foods andrequire fry stability.

Flavor stability is determined by sensory analysis of an oil sampleperiodically taken from an oil held under defined conditions. Forexample, oils may be stored in an oven at an elevated temperature toaccelerate the aging. The oil may also be stored at room temperature.However, the length of time required for testing renders this method tobe less useful. Flavor stability is measured by the time it takes forthe flavor of the oil to degrade to an established numerical score. Thesensory panel rates the oil or food product from 1 (unacceptable) to 9(bland). A rejection point is selected where the oil or food productbegins to show deterioration. Bottled cooking oils and salad dressingsrequire high flavor stability.

Photooxidative stability is determined from analysis of oil samplestaken periodically from oil stored under defined light and temperatureconditions. Photooxidative stability is reflected in the duration oftime it takes for the flavor of the oil to degrade to a set score.Bottled cooking oils require high photooxidative stability.

Shelf-life stability is determined by the analysis of food samplescooked in the oil, then packaged and stored in an oven at an elevatedtemperature to accelerate aging. "Shelf-life" is the time it takes forthe flavor of the food to degrade to give a set score. Oils for friedsnacks require shelf-life stability.

As used herein, a "line" is a group of plants that display little or nogenetic variation between individuals for at least one trait ofinterest. Such lines may be created by several generations ofself-pollination and selection, or vegetative propagation from a singleparent using tissue or cell culture techniques. As used herein, theterms "cultivar" and "variety" are synonymous and refer to a line whichis used for commercial production.

"Saturated fatty acid" refers to the combined content of palmitic acidand stearic acid. "Polyunsaturated fatty acid" refers to the combinedcontent of linoleic and α-linolenic acids. The term "room odor" refersto the characteristic odor of heated oil as determined using theroom-odor evaluation method described in Mounts (J. Am. Oil Chem. Soc.,56:659-663, 1979).

A "population" is any group of individuals that share a common genepool. The term "progeny" as used herein means the plants and seeds ofall subsequent generations resulting from a particular designatedgeneration.

The term "selfed" as used herein means self pollinated.

"Generic canola oil" refers to a composite blend of oils extracted fromcommercial varieties of rapeseed currently known, which varietiesgenerally exhibited at a minimum 8-10% α-linolenic acid content, amaximum of 2% erucic acid and a maximum of 30 μmol/g total glucosinolatelevel. The seed from each growing region is graded and blended at thegrain elevators to produce a uniform product. The blended seed is thencrushed and refined, the resulting oil being a blend of varieties andsold for use. Table 1 shows the distribution of canola varieties seededas percentage of all canola seeded in Western Canada in 1990. Canada isa leading producer and supplier of canola seed and oil.

                  TABLE 1                                                         ______________________________________                                        Distribution of Canola Varieties                                                Grown in Western Canada in 1990                                                   Canola Variety                                                                           Percent of Seeded Area                                       ______________________________________                                        B. campestris                                                                   Candle 0.4                                                                    Colt 4.4                                                                      Horizon 8.5                                                                   Parkland 2.5                                                                  Tobin 27.1                                                                    B. napus                                                                      Alto 1.1                                                                      Delta 0.9                                                                     Global 0.9                                                                    Legend 18.2                                                                   Pivot 0.1                                                                     Regent 0.5                                                                    Stellar 0.2                                                                   Tribute 0.4                                                                   Triton 0.7                                                                    Triumph 0.2                                                                   Westar 29.5                                                                   Others 4.4                                                                  ______________________________________                                         Source: Quality of Western Canadian Canola1990 Crop Year. Bull. 187,          DeClereg et al., Grain Research Laboratory, Canadian Grain Commission,        1404303 Main Street, Winnipeg, Manitoba, R3C 3G8.                        

"Canola" refers to rapeseed (Brassica) which has an erucic acid(C_(22:1)) content of at most 2 percent by weight based on the totalfatty acid content of a seed, preferably at most 0.5 percent by weightand most preferably essentially 0 percent by weight and which produces,after crushing, an air-dried meal containing less than 30 micromoles(μmol) per gram of defatted (oil-free) meal.

The term "canola oil" is used herein to describe an oil derived from theseed of the genus Brassica with less than 2% of all fatty acids aserucic acid.

Genetic crosses are made with defined germplasm to produce the canolaoil of the present invention having reduced polyunsaturated fatty acids,improved flavor stability, fry stability, oxidative stability,photooxidative stability and shelf-life stability, in a high yieldingSpring canola background. IMC 129, a Spring canola variety with higholeic acid in the seed oil is crossed with IMC 01, a Spring canolavariety with low α-linolenic acid in the seed oil. Flower buds of the F₁hybrid are collected for microspore culture to produce a dihaploidpopulation. The dihaploid plants (genetically homozygous) are selectedwith high oleic, and reduced linoleic and α-linolenic acids in the seedoil and field tested for stability of the fatty acids and yield.

After five generations of testing in the field and greenhouse a highyielding selection with fatty acid stability in multiple environments isselected. Seed of selection is grown in isolation, harvested, and theoil extracted and processed to produce a refined, bleached anddeodorized oil using known techniques. The oil produced was found to befunctionally superior in oxidative stability and fry stability relativeto a commercial-type, generic canola oil processed under similarconditions.

The canola oil of the present invention has an oxidative stability asdetermined by Active Oxygen Method (AOM) values of from about 35 toabout 40 hours. This is significantly higher than any known pilot plantor commercial processed canola oil. The increase is 45 to 60% abovecommercial type generic canola oil.

Under extended frying conditions, canola oil of the invention issignificantly lower than commercial-type generic canola in the oxidativetests for total polar material, free fatty acids, color development andp-anisidine value. The oil remains significantly lower in all oxidativeparameters tested after 32 and 64 hours of frying.

The oil has about 12% and about 23% total polar materials at 32 and 64hours of frying, respectively. This represents a 34% decrease at 32hours and a 17% decrease at 64 hours compared to commercial type genericcanola oil. The total polar materials are a measure of the total amountof secondary by-products generated from the triacylglycerols as aconsequence of oxidations and hydrolysis, and their reduction indicatesimproved oxidative stability.

Oil of the invention has a reduced content of free fatty acids of about0.3% and about 0.7% at 32 and 64 hours of frying, respectively. Thisrepresents a 37% decrease at 32 hours and a 23% decrease at 64 hourscompared to commercial type generic canola oil. The level of free fattyacids is a measure of oxidation and hydrolysis of the triacylglycerolsand their reduction also indicates improved oxidative stability.

The color developed in an oil during frying is also an indication oftriacylglycerol oxidation. The oil of the present invention demonstrateda reduced level of color development. The Lovibond color is about 2.7red and about 6.7 red at 32 and 64 hours of frying, respectively. Thisrepresents a 38% decrease at 32 hours and a 47% decrease at 64 hourscompared to commercial type generic canola oil.

Reduced development of aldehydes during frying also indicate improvedoxidative stability and are measured by the p-anisidine value inabsorbance/g at 350 nm. The oil has a p-anisidine value of about 112absorbance/g after 32 hours of frying and of about 125 absorbance/gafter 64 hours of frying. This represents a 32% decrease at 32 hours anda 14% decrease at 64 hours compared to commercial type generic canolaoil.

The oil additionally has improved oxidative stability and fryingstability without hydrogenation or the addition of antioxidants. Theimproved oxidative and fry stability results in increased flavorstability of the oil. Addition of antioxidants to the oil will furtherincrease oxidative stability.

Oil of the invention may be produced from, for example, a Brassica napusplant designated as IMC 130 or from a Brassica napus line designated asA13.30137. The seed oil has reduced amounts of total C_(16:0) (palmitic)and C_(18:0) (stearic) saturates of less than 6.5%, oleic acid from 74to 80%, linoleic acid from 5 to 12%, α-linolenic acid from 2.0 to 5.0%and erucic acid of less than 1%.

The oil of the present invention is especially suitable for use in foodapplications, in particular for frying foods, due to its superioroxidative stability and fry stability. Due to its non-hydrogenatednature, it is especially desirable for positive human healthimplications. The seeds, plant lines, and plants of the presentinvention are useful for the production of the non-hydrogenated canolaof this invention.

EXAMPLES

The present invention is further defined in the following Examples, inwhich all parts and percentages are by weight and degrees are Celsius,unless otherwise stated. It should be understood that these Examples,while indicating preferred embodiments of the invention, are given byway of illustration only.

Example 1

A cross of IMC 129×IMC 01 was conducted to obtain A13.30038, a dihaploidSpring canola variety. IMC 129 (U.S. PVP Certificate No. 9100151) is aSpring canola Brassica napus variety possessing high oleic acid (>75%)in the seed oil. IMC 01 is a Spring canola Brassica napus varietypossessing low α-linolenic acid (<2.5%) in the seed oil. A genetic crosswas made in 1989 to combine the low α-linolenic and high oleic acidtraits in a high yielding background for commercial production.

The F₁ plants (IMC 129×IMC 01) were grown in a growth chamber at 12°/6°C. (day/night) with 16 hours of illumination. Flower buds between 2-3.5mm were selected for microspore isolation. The microspores were isolatedand cultured to produce embryos using the method of Lichter, R., Z.Pflanzenphysiol, 105:427-434 (1982). Plants regenerated from themicrospores were grown in the greenhouse until flowering. Haploid plantswere treated with colchicine to induce chromosome doubling. Dihaploidplants were self-pollinated.

Seed (DH₁) of the selfed dihaploid plants were harvested in 1990 andanalyzed in bulk for fatty acid composition via gas chromatography.Following fatty acid analysis, seed designated A13.30038 was identifiedwith high oleic and low α-linolenic acids (Table 2). The DH₁ seed wasplanted in the greenhouse and self-pollinated. The harvested DH₂ seedgeneration maintained the selected fatty acid composition. In 1991 theDH₂ seed was planted in Southeast Idaho to determine yield of the line.Plants in the field were self-pollinated to determine fatty acidstability. The DH₃ seed maintained the selected fatty acid compositionin the field. DH₃ seed of A13.30038 was increased under isolation tentsduring the Winter of 1991 in Southern California. The DH₄ seedmaintained the selected fatty acid stability and was increased inisolation (2 miles) in Southeastern Idaho during 1992 to further testoil quality and yield.

After the 1992 summer trial, A13.30038 was found to have improved yieldand stable fatty acid composition. This line was renamed IMC 130. Yielddata for line IMC130 is shown in Tables 13 and 14; the fatty acidcomposition over five generations is listed in Table 2.

                  TABLE 2                                                         ______________________________________                                        Fatty Acid Composition of                                                       A13.30038 over Five Generations                                               Fatty Acid Composition                                                        Generation C.sub.16:0                                                                            C.sub.18:0                                                                          C.sub.18:1                                                                          C.sub.18:2                                                                          C.sub.18:3                                                                          C.sub.22:1                       ______________________________________                                        DH.sub.1 3.8     2.8     80.5  6.6   2.3   0.0                                  DH.sub.2 3.8 2.8 77.8 8.4 3.3 0.0                                             DH.sub.3 3.6 2.2 80.0 7.5 2.8 0.0                                             DH.sub.4 3.3 1.9 79.3 8.9 3.6 0.0                                             DH.sub.5 3.6 2.9 76.2 10.3 3.4 0.0                                          ______________________________________                                    

The IMC 130 seed was crushed and the resulting oil processed using apilot plant at the POS Pilot Plant Corporation, 118 Veterinary Road,Saskatoon, Saskatchewan, Canada. The starting seed weight was 700 kg.All oils for which data is supplied were prepared under the sameconditions set forth below. To ensure good extraction of the oil theseed was tempered by spraying the seed with water to raise the moistureto 8.5%. The seed and water were blended and allowed to equilibrate. Theseed was flaked using smooth roller. A minimum gap setting was used toproduce a flake thickness of 0.23 to 0.27 mm. The oil cells were furtherruptured and enzymes deactivated by heating in a two tray cooker. Thetop tray was heated to 65-75° C. and the bottom tray to 91-95° C. usingdry heat. A sweeping arm was used to agitate the material.

The oil was pressed from the flaked seed using a Simon-Rosedowns 9.5 cmdiameter by 94 cm long screw press operating at a screw speed of 17 rpm.The crude oil was kept under nitrogen until further processing. Hexaneextraction was used to remove the oil from the press cake. The presscake was extracted using a total residence time of 90 min. and a solventto solids ration of 2.4:1. The crude solvent extracted oil was collectedand kept under nitrogen until further processing.

The crude press and solvent extracted oils were dried and filtered toremove solids prior to degumming. The oils were heated at 100° C. undera vacuum until foaming stopped. The oil was cooled to 65-75° C. and 0.8%of filter aid was added and filtered. The oil was water degummed toremove phosphatides from the oil. The blended press and solventextracted oils were heated to 60-70° C. and 2.0% of 80-100° C. water wasadded and mixed for 15 min. The oil was then centrifuged for gumremoval.

Alkali refining was used to remove the free fatty acids. Phosphoric acid(85%) was added to 0.25% of the water degummed oil held at 60-70° C. andmixed for 30 min. Sodium hydroxide was added to the acid treated oil toneutralize the free fatty acids. After a 15 min. retention time the oilwas heated to 75-80° C. and centrifuged.

Water washing was done to further remove soaps. The refined oil waswashed by adding 15% of 90-95° C. water to the oil and mixed for 15 min.The oil was maintained at 75-80° C. and centrifuged. The washed oil washeated to 60-65° C. and bleached using Englehard's `Grade 160` bleachingclay. The oil was heated to 105-110° C. and held under a vacuum for 30min. The oil was cooled to 60-65° C. and 20% of the clay weight wasadded as a filter aid.

The bleached oil was deodorized using a Johnson-Loft packed towercontinuous deodorizer. The oil deodorization temperature was 265° C. andthe feed rate was 200 kg/hr. The steam rate was 1% of the feed rate andthe system pressure was 0.16-0.18 kPa. The oil was preheated to 68-72°C. prior to being fed into the deareation vessel. The oil was cooled to41-42° C. prior to removal of the vacuum. The oil was stored undernitrogen at -20° C.

The IMC 130 oil was analyzed for fatty acid composition via gaschromatography along with commercially available canola oils. Table 3provides data on the fatty acid profiles of IMC 130 oil compared tocommercially available canola oils, IMC 129 (a high oleic acid oil), IMC144 (a typical generic canola oil) and Brand A (a typical generic canolaoil). The data demonstrates reduced levels of linoleic (C_(18:2)),α-linolenic (C_(18:3)), and total polyunsaturated fatty acids for IMC130.

                  TABLE 3                                                         ______________________________________                                        Fatty Acid Composition of                                                       Refined, Bleached and Deodorized Oils                                         Fatty Acid Composition (%)                                                    Variety   C.sub.16:0                                                                            C.sub.18:0                                                                         C.sub.18:1                                                                          C.sub.18:2                                                                         C.sub.18:3                                                                          Total Polys*                        ______________________________________                                        IMC 130 3.6     2.9    76.2  10.3 3.4   13.7                                    IMC 144 2.9 2.1 62.6 19.5 8.1 27.6                                            IMC 129 3.9 2.0 78.8  7.7 3.9 11.6                                            Brand A 3.8 2.0 60.9 19.9 9.1 28.0                                          ______________________________________                                         *Total polyunsaturated acids                                             

Oils were evaluated for AOM hours under the methods outlined in theAmerican Oil Chemists' Society (AOCS) Official Method Cd 12-57 for FatStability:Active Oxygen Method (re'vd. 1989). The degree of oxidativestability is rated as the number of hours to reach a peroxide value of100. Each oil sample was prepared in duplicate.

The IMC 130 oil was found to have significantly higher AOM hours thanother oils tested, IMC 144, IMC 01, and IMC 129 after similar pilotplant processing. The IMC 144, IMC 01, and IMC 129 oils are currentlycommercially available from InterMountain Canola, Cinnaminson, N.J.(Table 4). IMC 129 (a high oleic variety) and IMC 01 (a low α-linolenicvariety) were the parent lines crossed to generate IMC 130. IMC 144 is atypical generic canola oil. IMC 130 oil has a minimum of 37 AOM hourswhich is significantly greater than commercial-type, generic canola at22 AOM hours. Typically, pilot plant processing of oils tends to reduceAOM hours as the process is much harsher on the oil than commercialprocessing. The greater oxidative stability of IMC 130 can be attributedto a lower polyunsaturated fatty acid content than the IMC 144 oil ortypical generic canola oil (Table 3). The greater oxidative stabilityover the high oleic IMC 129 oil, which is similar in fatty acidcomposition to IMC 130 oil, indicates that oxidative stability is notsolely related to fatty acid content.

                  TABLE 4                                                         ______________________________________                                        AOM Hours of Pilot Plant Processed Canola Oils                                  Process  IMC 144   IMC 01   IMC 129  IMC 130                                  Method (Generic) (LOW ALA)* (High Oleic) (Example 1)                        ______________________________________                                        Pilot Plant                                                                          15-22     20-22      16       37-40                                    ______________________________________                                         *ALA = linolenic acid                                                    

EXAMPLE 2

The oil of Example 1 and IMC 144, a generic canola oil, were subjectedto further testing to determine frying stability as measured byoxidative degradation during frying.

1900 g of each test oil was placed in a clean six quart capacity 110volt, commercial fryer (Tefal Super Cool Safety Fryers Model 3617). Oiltemperature was maintained at 190° C. for eight hours each day.Temperature was controlled to ±5° C. of the target temperature using aCole-Palmer temperature controller.

Commercially available frozen french fries (100 g) were fried for fourmin, three times per eight hour day in each test oil. 50 mL of oil wereremoved each day for chemical analysis to determine the amount ofoxidative degradation. Fresh oil was added to the fryer each day toreplace the amount removed for samples or lost through absorption onfries and retention on process equipment.

The oxidative parameters of the oils after frying were measured usingprocedures established by the AOCS (Official Methods and RecommendedPractices of the American Oil Chemists' Society, Fourth Edition (1989)Ed., D. Firestone, Published by the American Oil Chemists' Society,Champaign, Ill.). These oxidative parameters are indicators of frystability.

The oil was analyzed after frying for Total Polar Material (% TPM), FreeFatty Acids (% FFA), Color Development and Para-Anisidine Value (P-AV).The resulting data at 0, 32, and 64 hours of frying is reported in Table5. The IMC 130 values reported in Table 5 are significantly lower thanthe IMC 144 values with a 95% degree of confidence. This demonstratesthe improved fry stability of IMC 130 oil over commercial IMC 144 canolaoil.

The percent of total polar material was determined using the AOCSOfficial Method Cd 20-91. The total polar materials are a measure of thetotal amount of secondary by-products generated from thetriacylglycerols as a consequence of oxidations and hydrolysis. Reducedaccumulation of total polar material by an oil indicates improvedoxidative stability. IMC 130 was significantly reduced in total polarmaterial after 32 and 64 hours of frying in comparison to commercialcanola oil.

The percent of free fatty acids were determined using AOCS OfficialMethod Ca 5a0-40. Free fatty acids generated in the oil during frying isa measure of oxidation and hydrolysis of the triacylglycerols. Reducedfree fatty acids during frying of an oil indicates improved oxidativestability. In comparison to commercial canola oil, IMC 130 oil wassignificantly reduced in free fatty acids after 32 and 64 hours offrying.

Color development was measured using the AOCS Official Method Cc 13b-45using a Lovibond Tintometer and is reported as red color. Red colordevelopment in the oil during frying is an indication of triacylglyceroloxidation. Oils with reduced red color development will have improvedoxidative stability. IMC 130 oil had significantly less red colordevelopment than the commercial oil after 32 and 64 ours of frying.

The para-anisidine value was measured using the AOCS Official Method Cd18-90. Aldehydes are generated during frying from the oxidation of thetriacylglycerol are measured by the p-anisidine value. The p-anisidinevalue is 100 times the optical density measured at 350 nm in a 1 cm cellof a solution containing 1.00 g of the oil in 100 mL of a mixture ofsolvent and reagent according to the method referenced, and is inabsorbance/g. Reduced development of aldehydes during frying is anindicator of improved oxidative stability of the oil. IMC 130 hadsignificantly less aldehyde content after 32 and 64 hours of frying thanthe IMC 144 canola oil, a typical commercial generic canola oil.

                  TABLE 5                                                         ______________________________________                                        Effects of Frying on Oxidative Parameters                                                 IMC     IMC   IMC   IMC    IMC   IMC                                Oxidation 130 at 144 at 130 at 144 at 130 at 144 at                           Parameter 0 Hrs. 0 Hrs. 32 Hrs. 32 Hrs. 64 Hrs. 64 Hrs.                     ______________________________________                                        % TPM.sup.a                                                                           5.3     5.8     12.0  18.2   22.6  27.2                                 % FFA.sup.b 0.01 0.01 0.29 0.46 0.74 0.96                                     Lovibond 0.3 0.5 2.7 4.3 6.7 12.5                                             Color.sup.c                                                                   P-AV.sup.d 0.27 1.65 112 164 125 145                                        ______________________________________                                         .sup.a Total polar material, %                                                .sup.b Free fatty acids, %                                                    .sup.c Lovibond color, red                                                    .sup.d paraanisidine value, absorbance/g                                 

EXAMPLE 3

The oil of Example 5 plus the following oils were subjected to furthertesting.

IMC 129--high oleic canola oil

Quality analysis of each oil is found in Table 6.

                  TABLE 6                                                         ______________________________________                                        Oil Analysis                                                                                   IMC 130  IMC 129                                             ______________________________________                                        Red Color        0.8      0.3                                                   Yellow Color 6 2                                                              para-anisidine value.sup.3 2.58 0.66                                          Peroxide Value.sup.1 0.3 0.3                                                  Totox Value.sup.2 3.18 1.24                                                   % Polars 0.69 .64                                                             % Polymers 0.013 0.010                                                        % Free Fatty Acids 0.022 0.014                                                % C16:0 3.5 3.6                                                               % C18:0 2.3 2.0                                                               % C18:1 73.4 75.7                                                             % C18:2 11.1 9.5                                                              % C18:3 5.7 6.2                                                             ______________________________________                                         .sup.1 Peroxide Value, meq/Kg                                                 .sup.2 Totox Value = paraanisidine value + 2 (peroxide value)                 .sup.3 Paraanisidine value, absorbance per gram                          

Oxidative stability of the oil in Example 5 was demonstrated bymeasuring the increase in Peroxide Value and in para-Anisidine Valuegenerated under accelerated aging conditions using a modified Schaaloven test. The test oil (200 g) was placed in an 500 ml uncovered amberglass bottle with a 4.3 cm opening, and placed in a 60° C. convectionoven. One bottle was prepared for each evaluation. Results are found inTable 7 and Table 8.

The peroxide value was measured using the AOCS Official Method Cd 8b-90.Hydroperoxides generated from oxidation of the triacylglycerols weremeasured by the peroxide value. The peroxide value was expressed interms of milliequivalents of peroxide per 1000 grams of sample (meq/Kg).Reduced development of hydroperoxides during storage was an indicator ofimproved oxidative stability.

The para-anisidine value was measured using the AOCS Official Method Cd18-90. Aldehydes generated from the oxidation of the triacylglycerol wasmeasured by the p-anisidine value. The p-anisidine value was 100 timesthe optical density measured at 350 nm in a 1 cm cell of a solutioncontaining 1.00 g of the oil in 100 ml of a mixture of solvent andreagent according to the method referenced, and is absorbance/g. Reduceddevelopment of aldehydes during storage was an indicator of improvedoxidative stability of the oil.

                  TABLE 7                                                         ______________________________________                                        Accelerated Aging-Oxidative Stability                                           Increase in Peroxide Value, Milliequivalents per kg                           Days in oven:     IMC 130  IMC 129                                          ______________________________________                                        3               0.9      0.7                                                    6 2.1 2.3                                                                     9 12.6 14.9                                                                   12 16.1 22.1                                                                  15 24.5 29.7                                                                ______________________________________                                    

                  TABLE 8                                                         ______________________________________                                        Accelerated Aging-Oxidative Stability                                           Increase in para-Anisidine Value, Absorbance per g                            Days in oven:     IMC 130  IMC 129                                          ______________________________________                                        6               0.1      0.2                                                    9 2.0 3.1                                                                     12 4.8 6.9                                                                    15 6.9 10.2                                                                 ______________________________________                                    

EXAMPLE 4

The oil of Example 5 plus the following oils were tested for oxidativestability.

Brand T--commercially available high oleic sunflower oil

Brand A--commercially available generic canola oil

Quality analysis of each oil is found in Table 9.

Oxidative stability of the oils described in Table 9 were determinedunder accelerated aging conditions using a modified Schaal oven testwhich accelerates oxidation. Oxidative stability was demonstrated by theincrease in peroxide value over the test period. Schaal oven tests showthat each day of accelerated oxidation at 60° C. is equivalent to amonth of oxidation under ambient storage conditions. Using thiscorrelation three days of accelerated aging is equivalent to threemonths of ambient storage. The test oil (200 g) was placed in a 500 mluncovered amber glass bottle with a 4.3 cm opening, and placed in a 60°C. convection oven. One bottle was prepared for each evaluation. Thetest was carried out to six days to simulate actual product shelf-lifeof six months. Results are found in Table 10.

The peroxide value was measured using the AOCS Official Method Cd 8b-90.Hydroperoxides generated from oxidation of the triacylglycerols weremeasured by the peroxide value. The peroxide value was expressed interms of milliequivalents of peroxide per 1000 grams of sample (meq/Kg).Reduced development of hydroperoxides during storage is an indicator ofimproved oxidative stability. IMC 130 had significantly less peroxidedevelopment after three days and six days in the Schaal oven test thanBrand T, a high oleic sunflower oil with lower polyunsaturates (C_(18:2)+C_(18:3)), and Brand A, a typical commercial generic canola oil.

                  TABLE 9                                                         ______________________________________                                        Quality Analysis of Test Oils                                                               IMC 130     Brand T Brand A                                     ______________________________________                                        Red Color     0.8         0.8     0.7                                           Yellow Color 6 6 5                                                            para-anisidine value.sup.3 2.58 4.21 2.32                                     Peroxide Value.sup.1 0.3 0.6 0.7                                              Totox Value.sup.2 3.18 5.41 3.72                                              % Polars 0.69 0.90 0.36                                                       % Polymers 0.013 0.004 0.01                                                   % Free Fatty Acids 0.022 0.016 0.013                                          % C16:0 3.5 3.3 4.0                                                           % C18:0 2.3 4.2 2.0                                                           % C18:1 73.4 81.7 62.5                                                        % C18:2 11.1 8.8 18.3                                                         % C18:3 5.7 0.3 7.7                                                         ______________________________________                                         .sup.1 Peroxide Value, meq/Kg                                                 .sup.2 Totox Value = paraanisidine value + 2 (peroxide value)                 .sup.3 Paraanisidine value, absorbance/g                                 

                  TABLE 10                                                        ______________________________________                                        Accelerated Aging-Oxidative Stability                                           Increase in Peroxide Value, Meq/Kg                                              Days in Oven:                                                                            IMC 130      Brand A                                                                              Brand T                                    ______________________________________                                        3          0.8          6.2      3.2                                            6 1.8 14.4 7.0                                                              ______________________________________                                    

EXAMPLE 5

IMC 130 canola seed was produced during the 1993 growing season of theNorthwestern U.S. The resulting IMC 130 canola seed was cleaned throughcommercial seed cleaning equipment to remove foreign matter consistingof weed seeds, canola plant material, immature canola seed and other noncanola matter.

The cleaned IMC 130 canola seed was crushed and the resulting oil wasprocessed at SVO Specialty Products, Inc., One Mile East, Culbertson,Mo. Approximately 361 tons of IMC 130 canola seed was crushed under theprocessing conditions outlined below.

Whole canola seed was passed through a double roll Bauermeister flakingrolls with smooth surface rolls available from Bauermeister Inc.,Memphis, Tenn. 38118. The roll gap was adjusted so as to produce acanola flake 0.25 to 0.30 mm thickness. Flaked canola seed was conveyedto a five tray, 8 foot diameter stacked cooker, manufactured by CrownIron Works, Minneapolis, Minn. 55440. The flaked seed moisture wasadjusted in the stacked cooker to 5.5-6.0%. Indirect heat from the steamheated cooker trays was used to progressively increase the seed flaketemperature to 80-90° C., with a retention time of approximately 20-30minutes. A mechanical sweep arm in the stacked cooker was used to ensureuniform heating of the seed flakes. Heat was applied to the flakes todeactivate enzymes, facilitate further cell rupturing, coalesce the oildroplets and agglomerate protein particles in order to ease theextraction process.

Heated canola flakes were conveyed to a screw press from AndersonInternational Corp., Cleveland, Ohio 44105 equipped with a suitablescrew worm assembly to reduce press out approximately 70% of the oilfrom the IMC 130 canola flakes. The resulting press cake contained15.0-19.0% residual oil.

Crude oil produced from the pressing operation was passed through asettling tank with a slotted wire drainage top to remove the solidsexpressed out with the oil in the screw pressing operation. Theclarified oil was passed through a plate and frame filter to remove theremaining fine solid canola particles. The filtered oil was combinedwith the oil recovered from the extraction process before oil refining.

Canola press cake produced from the screw pressing operation wastransferred to a FOMM basket extractor available from French Oil Milland Machinery Co., Piqua, Ohio 45356, where the oil remaining in thecake was extracted with commercial n-Hexane at 55° C. Multiple countercurrent hexane washes were used to substantially remove the remainingoil in the press cake, resulting in a press cake which contained1.2-2.3%, by weight, residual oil in the extracted cake. The oil andhexane mixture (miscella) from the extraction process was passed througha two stage rising film tube type distillation column to distill thehexane from the oil. Final hexane removal from the oil was achieved bypassing the oil through a stripper column containing disk and doughnutinternals under 23-26 in. Hg vacuum and at 107-115° C. A small amount ofstripping steam was used to facilitate the hexane removal. The canolaoil recovered from the extraction process was combined with the filteredoil from the screw pressing operation, resulting in blended crude oil,and was transferred to oil processing.

In the oil processing the crude oil was heated to 66° C. in a batchrefining tank to which 0.15% food grade phosphoric acid, as 85%phosphoric acid, was added. The acid serves to convert the nonhydratable phosphatides to a hydratable form, and the chelate minormetals that are present in the crude oil. The phosphatides and the metalsalts are removed from the oil along with the soapstock. After mixingfor 60 minutes at 66° C., the oil acid mixture was treated withsufficient sodium hydroxide solution (12° Be) to neutralize the freefatty acids and the phosphoric acid in the acid oil mixture. Thismixture was heated to 71° C. and mixed for 35 minutes. The agitation wasstopped and the neutralized free fatty acids, phosphatides, etc.(soapstock) were allowed to settle into the cone bottom of the refiningtank for 6 hours. After the settling period, the soapstock was drainedoff from the neutralized oil.

A water wash was done to reduce the soap content of the oil by heatingthe oil to 82° C. and by adding 12% hot water. Agitation of the mixturecontinued for 10 minutes. The mixture was allowed to settle out for 4hours at which time the water was drained off the bottom of the refiningvessel.

The water washed oil was heated to 104-110° C. in a vacuum bleachervessel maintained at 24-26 in. Hg vacuum. A slurry of the IMC 130 canolaoil and Clarion 470 bleaching clay available from American ColloidCompany, Refining Chemicals Division, Arlington Heights, Ill. 60004, wasadded to the oil in the vacuum bleacher. This mixture was agitated for20 minutes before filtering to remove the bleaching clay. The clayslurry addition was adjusted to provide a Lovibond color AOCS OfficialMethod Cc 136-4 of less than 1.0 red units when the oil was heated to288° C. under atmospheric pressure. Nitrogen was injected into thefiltered bleached oil and maintained under a nitrogen blanket until theoil was deodorized.

Refined and bleached IMC 130 canola oil was deodorized in asemi-continuous Votator deodorizer tower at a rate of approximately7,000 pounds per hour. The deodorization temperature was maintained at265-268° C. with a system pressure of 0.3-0.5 mm Hg absolute pressure.Approximately 1-1.5% sparge steam was used to strip off the free fattyacids, color bodies, and odor components. Retention time in thedeodorizer was 50-70 minutes. The deodorized oil was cooled to 45-50° C.and nitrogen was injected prior to removal of the vacuum. The deodorizedoil was stored under a nitrogen blanket.

The resulting IMC 130 deodorized oil was analyzed for fatty acidcomposition via gas chromatography. The percent fatty acids wereC_(16:0) of 3.6%, C_(18:0) of 2.2%, C_(18:1) of 74.3%, C_(18:2) of11.9%, C_(18:3) of 4.8% and total polyunsaturated of 16.7%. These datacan be compared to the values for IMC 144, IMC 129 and Brand A as shownin Table 3. The data demonstrate that IMC 130 maintains reduced levelsof linolenic acid (C_(18:2)), α-linolenic (C_(18:3)), and totalpolyunsaturated fatty acids when compared to typical generic canola oilsIMC 144 and Brand A.

Table 11 provides data on the AOM hours of the IMC 130 oil processed asdescribed above (the commercial process in 1993), compared tocommercially available canola oils, IMC 129 (a high oleic acid oil), IMC144 (a typical generic canola oil) and IMC 01 (a low α-linolenic oil).The IMC 130 oil was evaluated for AOM hours under the methods outlinedin the American Oil Chemists' (AOCS) Official Method Cd 12-57 for FatStability: Active Oxygen Method (re'vd 1989). The degree of oxidativestability is rated as the number of hours to reach a peroxide value of100. The higher AOM hours of IMC 130 reflects its greater oil stability.Each oil sample was prepared in duplicate.

                  TABLE 11                                                        ______________________________________                                        AOM Hours of Commercially Processed Canola Oils                                 Process   IMC 144   IMC 01  IMC 129  IMC 130                                  Method (Generic) (Low ALA)* (High Oleic) (Example 5)                        ______________________________________                                        Commercial                                                                            15-18     30        30       37.5                                     ______________________________________                                         *ALA = linolenic acid                                                    

EXAMPLE 6

Another doubled haploid line was identified in the DH₂ generation of theIMC129×IMCO1 cross of Example 1 and termed A13.30137. The line wasself-pollinated and selected as described in Example 1 for fivegenerations. A13.30137 was tested for fatty acid stability and yieldpotential in research plots and strip trials in Idaho, Montana, andWashington. It appeared homogeneous and morphological variation was notobserved during the production of foundation seed.

A13.30137 matured about two days earlier than IMC130 and was about 10 cmshorter than IMC130. The fatty acid composition of A13.30137 seeds wasdetermined over 6 generations as described in Example 1 and is shown inTable 12. The yield performance of A12.30137 in research plots and striptrials is shown in Table 13 for the DH₅ generation and in Table 14 forthe DH₇ generation.

                  TABLE 12                                                        ______________________________________                                        Fatty Acid Composition of A13.30137                                             from DH.sub.2  to DH.sub.7  Generation                                               Fatty Acid Composition                                               Generation                                                                             C.sub.16:0                                                                            C.sub.18:0                                                                            C.sub.18:1                                                                          C.sub.18:2                                                                          C.sub.18:3                                                                          C.sub.22:1                         ______________________________________                                        DH2      3.8     2.1     76.2  11.5  3.2   0.00                                 DH3 3.4 1.9 76.8 10.7 3.7 0.00                                                DH4 3.2 1.8 77.1  9.8 3.5 0.00                                                DH5* 3.5 2.2 75.0 10.1 5.3 0.00                                               DH6* 3.5 1.7 75.3 10.2 4.9 0.00                                               DH7 3.6 2.4 76.7 10.2 3.8 0.00                                              ______________________________________                                         *Lower temperatures during growing season.                               

                  TABLE 13                                                        ______________________________________                                        Yield Performance of A13.30137 DH.sub.5  Generation                                Line Name    Yield (lb/acre)                                                                          % of Westar                                      ______________________________________                                        Hyola 401     2,171      118                                                    A13.30137 1,879 102                                                           IMC129 1,865 102                                                              Westar 1,835 100                                                              Legend 1,764 96                                                               IMC130 1,573 86                                                               Global 1,526 83                                                             ______________________________________                                    

                  TABLE 14                                                        ______________________________________                                        Yield Performance of A13.30137 DH.sub.7  Generation                                Line Name    Yield (lb/acre)                                                                          % of Checks*                                     ______________________________________                                        Cyclone       1,960      131                                                    Hyola 401 1,876 126                                                           A13.30137 1,871 122                                                           Delta 1,859 121                                                               Legend 1,804 118                                                              IMC129 1,783 110                                                              IMC130 1,625 96                                                               Excel 1,578 93                                                              ______________________________________                                         *Average combined performance of Delta, Cyclone, Excel and Legend = 100. 

What is claimed is:
 1. A non-hydrogenated canola oil having apolyunsaturated fatty acid content of from about 7% to about 17%, anoleic acid content of about 74% to about 80% and an oxidative stabilityof from about 35 to about 40 AOM hours in the absence of addedantioxidants.
 2. The oil of claim 1 wherein said oil has an increase inthe percentage of total polar materials of about 6.7% after 32 hours offrying and about 17.3% after 64 hours of frying.
 3. The oil of claim 1wherein said oil has an increase in the percentage of free fatty acidsof about 0.28% after 32 hours of frying and about 0.73% after 64 hoursof frying.
 4. The oil of claim 1 wherein said oil has an increase inLovibond color value of about 2.4 red after 32 hours of frying and about6.4 red after 64 hours of frying.
 5. The oil of claim 1 wherein said oilhas an increase in para-anisidine value of about 112 absorbance/g after32 hours of frying and about 125 absorbance/g after 64 hours of frying.6. The oil of claim 1 wherein said oil has a peroxide value thatincreases by a maximum of about 24.5 Meq/Kg after accelerated aging for15 days.
 7. The oil of claim 1 wherein said oil has a para-anisidinevalue that increases by a maximum of about 6.9 absorbance/g afteraccelerated aging for 15 days.
 8. The oil of claim 1 wherein said canolaoil has a linoleic acid content of from about 5% to about 12%.
 9. Theoil of claim 8 wherein said canola oil has an α-linolenic acid contentof from about 2% to about 5%.
 10. A method of producing a canola oil,comprising the steps of:(a) crushing canola seeds having apolyunsaturated fatty acid content of from about 7% to about 17% anoleic acid content of about 74% to about 80%; and (b) extracting saidcanola oil from said crushed seeds, said oil having an oxidativestability of from about 35 to about 40 AOM hours in the absence of addedantioxidants.
 11. The method of claim 10, wherein said seeds have alinoleic acid content of from about 5% to about 12%.
 12. The method ofclaim 11, wherein said seeds have an α-linolenic acid content of fromabout 2% to about 5%.